(1) Field of the invention
The present invention relates to a graphic editing apparatus and method, and more particularly, to a graphic editing apparatus and method for creating or editing graphics on a screen such as animated images. Regarding the editing of graphics on the screen, there are several kinds of edits such as change of position, deformation, such as deforming a circle to an ellipse, enlargement or reduction, rotation, change of state such as color or brightness, and others.
(2) Description of the Related Art
In the past, a graphic editing apparatus based on a computer has handled a moving graphic such as an animated image according to a method in which a position of a graphic on a display unit at each time instant is described using a predetermined script or a method in which all the positions or shapes of a graphic at respective time instants are designated independently.
According to the former method, the relationships between the position of a graphic and time instant must be expressed as equations and position change information must be designated. It is therefore hard to determine the relationships between the time instant and position of a graphic during creating or editing graphics. In particular, creating or a editing a plurality of varying graphics is very hard to do. It is also hard to designate finely-varying states. Especially, editing work for varying a plurality of graphics simultaneously is very complex because time instants that are turning points of variations must be consistent among graphics.
In a method in which all shapes of a graphic varying time-sequentially are designated at respective time instants, the position and shape of a graphic must be delineated in every screen sent at each time instant (hereinafter, a frame). An enormous amount of labor is required for creating or editing. After creating or editing is completed, (1) when a graphic is to be moved more quickly or slowly, all frames must be re-edited, and (2) when time instants at which graphics vary synchronously are to be modified, all graphics in frames concerned must be re-edited. Thus, correction is hard to do.
When a conventional method is adopted, it is hard to edit not only a graphic varying time-sequentially but also a graphic varying depending on the value of a certain attribute.
In the prior arts, when a plurality of graphics of parts are to be created with the locations of the parts held intact, the locations of the parts are placed in memory and divided into groups. A group is regarded as a single graphic. Deformation such as enlargement, reduction, rotation, or the like, or movement is executed relative to the whole of a group.
In the conventional methods, however, when it is required to deform a particular one of graphics belonging to a group, the group graphics must be broken up to execute deformation. When a group is broken up, the positional relationships between the graphic and the other graphics are destroyed. During the deformation, an editor must deform or move the other graphics separately.
According to the specification of the PCT application No. PCT/JP 93/01303 filed on Sep. 10, 1993, a graphic editing apparatus and method, intended to solve the above mentioned problems, provides a means for creating or editing a graphic varying with the passage of time or the change in value of an attribute. The editing apparatus and method described in the PCT application No. PCT/JP 93/01303, performs editing of graphics in the following steps when editing a graphic related with another graphic or a group graphic containing a plurality of graphics, for example, when editing a first graphic related with a second graphic or the group graphic, each of which changes in accordance with the first graphic's movement, deformation, rotation or enlargement. The first step is to obtain a numerical attribute value for a reference line corresponding to a change in the first graphic. The second step is to edit the second graphic or the group graphic related with the first graphic, by means of a program, using the numeric attribute.
Here the reference line means a line created by using a mouse on a screen, on which line a movable point of a movable point graphic (cursor) moves in response to a change of a graphic in accordance with the graphic's movement, deformation, color change or others. Refer to the specification of the PCT application No. PCT/JP 93/01303 for further details. An attribute of a graphic means something changeable, for example, it can be an attribute of movement, deformation, color or the like regarded as a change based on the position of a graphic or a change based on the passage of time. An attribute value means numerical data when a change of the attribute is represented by the numerical data.
In accordance with conventional arts, it was necessary to execute the following steps when each graphic in a group graphic having a plurality of graphics is to be independently edited for movement, deformation, rotation, enlargement, or the like. The first step is to prepare two screens, a No.1 screen for showing a graphic in the group graphic to be independently edited for movement, deformation, rotation, enlargement, or the like, and a No.2 screen for showing the group graphic in which the location of the independently edited graphic is sliced. The second step is to independently edit the graphic on the No.1 screen. Third step is to make the No.1 and No.2 screens properly overlapped.
In accordance with conventional arts, when a lower graphic or a lower group graphic in a hierarchically structured graphic is to be independently edited by means of coordinate transformation, it was necessary to execute complicated procedures such as the programming of coordinate transformation for the lower graphic or the lower group graphic and displaying a graphic of the total hierarchical structure of the upper and lower graphics and/or the upper and lower group graphics after the programming.
In accordance with conventional arts, it was also necessary to execute the following steps when displaying numerical data or a change of a first graphic such as movement, deformation, rotation, enlargement, or the like, corresponding to a change of a second graphic such as movement, deformation, rotation, enlargement, or the like. The first step is to get numerical data from position data of a movable point on a reference line corresponding to the change of the second graphic. The second step is to directly display the data through a program or to display the other graphic to be changed in accordance with the numerical data.
The graphic editing apparatus and method of the prior arts requires much time and labor for editing graphics because complicated programming or positioning between overlapped screens or the like is required.